Amplifier circuitry is disclosed for receiving a differential signal and outputting a single-ended output signal. A travelling wave amplifier has a plurality of amplifier elements connected between an input transmission line and an output transmission line, each extending between first and second sides of the travelling wave amplifier. The input transmission line is configured to receive the first differential signal component at the first side and the output transmission line is configured to provide the single-ended output signal at the second side. A matched transmission line, which is configured to match at least some transmission properties of the input transmission line, receive the second differential signal component at the first end. A differential termination network is connected to both the input transmission line and matched and the matched transmission line and is configured to provide differential termination of signals received at the first and second termination inputs.

Amplifier circuitry is disclosed for receiving a differential signal and outputting a single-ended output signal. A travelling wave amplifier has a plurality of amplifier elements connected between an input transmission line and an output transmission line, each extending between first and second sides of the travelling wave amplifier. The input transmission line is configured to receive the first differential signal component at the first side and the output transmission line is configured to provide the single-ended output signal at the second side. A matched transmission line, which is configured to match at least some transmission properties of the input transmission line, receive the second differential signal component at the first end. A differential termination network is connected to both the input transmission line and matched and the matched transmission line and is configured to provide differential termination of signals received at the first and second termination inputs.

A differential constructive wave oscillator device including a single, continuous differential transmission line that is arranged into first and second parallel traces in the form of a Mobius loop. The continuous transmission line includes first and second crossover points, each of which provides for a point of inflection between the first and second traces. In each stage of the device, both the first and second traces of the transmission line carry the forward traveling wave signal from a differential input port to a differential output port. Each phase includes a differential delay section that provides for a phase shift between a signal on the first trace and a signal on the second trace. Each phase additionally includes a differential feedback amplifier that amplifies the forward traveling wave signal at the differential output port, generates a differential feedback signal, and routes the differential feedback signal to the differential input port.

A differential constructive wave oscillator device including a single, continuous differential transmission line that is arranged into first and second parallel traces in the form of a Mobius loop. The continuous transmission line includes first and second crossover points, each of which provides for a point of inflection between the first and second traces. In each stage of the device, both the first and second traces of the transmission line carry the forward traveling wave signal from a differential input port to a differential output port. Each phase includes a differential delay section that provides for a phase shift between a signal on the first trace and a signal on the second trace. Each phase additionally includes a differential feedback amplifier that amplifies the forward traveling wave signal at the differential output port, generates a differential feedback signal, and routes the differential feedback signal to the differential input port.

Distributed amplifier systems and methods are disclosed. An example distributed amplifier system includes first stage traveling wave amplifier (TWA) circuitry that is controllable to provide one of a first set of discrete gain settings. The first stage TWA circuitry includes a first input transmission line, a first output transmission line, and a first plurality of amplifiers coupled antiparallel between the first input transmission line and the first output transmission line. The first set of discrete gain settings has approximately constant logarithmic spacing.

A variable gain amplifier capable of stabilizing an average output potential of a differential output signal, improving power efficiency over a wide range of an amplitude of the differential input signal, and suppressing deterioration of a distortion rate is provided. The variable gain amplifier includes an amplifying circuit configured to amplify a differential input signal with a gain according to a gain control signal, and a current control circuit. The amplifying circuit has a first current source supplying a source current. The current control circuit adjusts a magnitude of the source current of the first current source according to a magnitude of the gain control signal.

A variable gain amplifier capable of stabilizing an average output potential of a differential output signal, improving power efficiency over a wide range of an amplitude of the differential input signal, and suppressing deterioration of a distortion rate is provided. The variable gain amplifier includes an amplifying circuit configured to amplify a differential input signal with a gain according to a gain control signal, and a current control circuit. The amplifying circuit has a first current source supplying a source current. The current control circuit adjusts a magnitude of the source current of the first current source according to a magnitude of the gain control signal.

A variable gain amplifier capable of stabilizing an average output potential of a differential output signal, improving power efficiency over a wide range of an amplitude of the differential input signal, and suppressing deterioration of a distortion rate is provided. The variable gain amplifier includes an amplifying circuit configured to amplify a differential input signal with a gain according to a gain control signal, and a current control circuit. The amplifying circuit has a first current source supplying a source current. The current control circuit adjusts a magnitude of the source current of the first current source according to a magnitude of the gain control signal.

A variable gain amplifier capable of stabilizing an average output potential of a differential output signal, improving power efficiency over a wide range of an amplitude of the differential input signal, and suppressing deterioration of a distortion rate is provided. The variable gain amplifier includes an amplifying circuit configured to amplify a differential input signal with a gain according to a gain control signal, and a current control circuit. The amplifying circuit has a first current source supplying a source current. The current control circuit adjusts a magnitude of the source current of the first current source according to a magnitude of the gain control signal.

A coaxial to waveguide transition includes a first rigid portion comprising an inverted hollow cone, a second rigid portion comprising a hollow tube, and a third rigid portion comprising a hollow cone. The first rigid portion has a first end and a second end, and tapers inward at a first angle from its first end towards its second end. The second rigid portion has a first end and a second end, with the first end being partially disposed within the second end of the first rigid portion. The third rigid portion has a first end and a second end, with the first end of the third rigid portion being partially disposed within the second end of the second rigid portion. The third rigid portion tapers outward at a second angle from its first end towards its second end, where the second angle is less than the first angle.